Some more in-progress pics - click photos for larger versions. I found a nice piece of spalted birch in the scrap pile that felt solid enough and cut it down to size with band saw and jointer.
I glued the pattern to the blank using a craft spray adhesive - sets fairly quickly as long as you don't soak the paper. Once the pattern was in place, I drilled holes in each of the areas to be removed. This pattern had a lot of very small areas, so I used a .035" bit, which is about the smallest hole that a 2R scroll saw blade will fit through. On the previous handles, I had room to drill larger holes and used a full-sized drill press. Since this bit was so small, I used a drill press attachment for my Dremel. Whatever you use, make sure your bit is square to the table.
Here's the handle after drilling all the holes. You can see an extra hole I drilled in the corner waste area to check that my bit was square before drilling into the pattern.
Next step was to use the scroll saw to cut out all the voids. You need to make sure your piece is a uniform thickness and that your saw table is square to the blade, otherwise the holes will wander and mess up the pattern on the back of the handle. Keep the blade as tight as you can without snapping it, and go slowly.
Handle is all roughed out now, and ready for carving. Will get more pictures once I start that phase, but it's time to get stuff ready for brew day tomorrow